Brouwer, a scientist at the University of California at Irvine, pioneered a method for deriving pure hydrogen from human waste, food scraps and other matter flushed from homes. While the aroma surrounding his prototype project at the Orange County Sanitation District’s Fountain Valley waste facility isn’t for everyone, for Brouwer it bears the whiff of promise.

“It smells like money,” he said.

That’s because the hydrogen made by Brouwer’s set-up can power fuel-cell cars that consume hydrogen and emit nothing but water vapor. Many automakers see this zero-emission technology as the most promising successor to gasoline engines. Already, hydrogen produced at the Southern California waste facility is being dispensed, on-site, from a pump used by drivers of several hundred fuel-cell cars now on the state’s roads.

That number is set to increase. In coming weeks, Hyundai Motor Co. plans to begin leasing a fuel-cell version of its Tucson crossover, which can travel about 480 kilometers on a tank of hydrogen.

The lease price will be $2,999 down and $499 a month, Hyundai said. That includes maintenance and complementary fuel from nearly a dozen hydrogen pumps around the state ― including the filling station at the Fountain Valley waste plant, which is just a mile away from Hyundai’s U.S. headquarters

The goings-on in Fountain Valley provide twin indications that hydrogen-powered cars, once seen as a promising but cost-prohibitive idea for the future, are becoming a reality as manufacturers perfect the technologies at what they say are increasingly reasonable prices.

Hyundai’s new vehicles mark one of the biggest fuel-cell pushes yet. The Tucsons, available to everyday drivers vetted by Hyundai, will join models from Toyota Motor Corp. and General Motors Co. already on trial in California, as well as Honda Motor Co. (7267) and Mercedes-Benz vehicles under lease there. More models are coming in 2015 from Toyota and Honda.

California, whose regulators want millions of emission-free cars and trucks to be sold by 2025, is providing its own boost.

While hydrogen is the universe’s most abundant element, pumps dispensing it are few and far between. California plans to spend $20 million each year for a decade to build about 100 stations to deliver compressed hydrogen. There are currently about 10 public stations clustered mainly in Southern California and the San Francisco Bay Area.

Most of that hydrogen is produced at industrial facilities that break down natural gas ― also known as methane, or CH4 ― in a process that steams out the carbon atoms and leaves behind pure hydrogen.

There’s more than one way to capture hydrogen, though, which is where Brouwer comes in with a technology reminiscent of “Back to the Future.” At the end of the 1985 blockbuster, the manic scientist character fuels his time-traveling DeLorean with a banana peel, stale beer and other trash.

In the system developed by Brouwer and fellow scientists from UC Irvine’s National Fuel Cell Research Center, real-life cars in 2014 run on pure hydrogen made in a process that starts with waste from Southern California toilets and sinks that arrives in a freely available and predictable flow.

First, sewage is separated into water and biosolids. The waste water is cleaned, filtered and treated for reuse. Solid waste is piped into airless tanks, where it is feasted upon by microbes. A byproduct of their digestion is a gas that’s 60 percent methane and about 40 percent carbon dioxide, Brouwer said.

Most of the methane from the digester tanks is burned at the plant for power generation. Some is filtered and piped into a unique, stationary “tri-generation” fuel-cell device, designed by the Irvine team, that produces electricity, heat and hydrogen. The hydrogen gas is then piped several hundred feet to the public pump where fuel-cell autos are refueled daily.

A decade ago, hydrogen’s allure as a low-carbon auto fuel led the former General Motors Corp. and other carmakers to predict that millions of fuel-cell autos would be on the road by now. While a mass market for the cars may be another decade away, automakers estimate that their combined investment in the technology of more than $10 billion during the past decade now has them on a path to commercialization.

Hyundai, South Korea’s largest automaker, works with affiliate Kia Motors Corp. on hydrogen R&D. Toyota and Bayerische Motoren Werke AG’s BMW have a fuel-cell technology alliance and Honda and GM last year formed a fuel-cell partnership. Daimler AG’s Mercedes-Benz, Ford Motor Co. and Nissan Motor Co. are also working together to advance the technology.

“Fuel cells are out of the lab, the experimental stage, but they’re not to the mainstream stage,” said Alan Baum, an analyst at Baum & Associates in West Bloomfield, Michigan, who tracks alternative-powertrain technologies. “Ten years from now this is a significant option.”

Hyundai’s Tucson, a compact sport-utility vehicle, reflects industry-wide advances in fuel-cell stacks and in the carbon-fiber tanks that hold hydrogen pressurized as high as 10,000 pounds per square inch.

Fuel-cell cars are propelled entirely by electric motors, like those in battery cars such as Tesla Motors Inc.’s Model S and Nissan’s Leaf hatchback. While battery-powered cars need to be plugged into power outlets to store up energy, fuel-cell models create their own energy by chemical reaction.

In a fuel cell, hydrogen gas passes through a stack of plastic membranes and platinum-dusted plates to produce electricity. Because of the precious metals needed, fuel-cell stacks remain expensive, as do the high-pressure tanks.

Prototype fuel-cell cars cost $1 million to make in the early 2000s. Honda, Hyundai, GM and Daimler all say mass-production will bring deeper reductions in the cost of fuel-cell cars, with Toyota saying its cost target for the hydrogen-powered sedan it will sell next year in the U.S. is about $50,000.

Hyundai’s California Tucson lease program will focus first on customers in Los Angeles and Orange Counties, which have the most hydrogen pumps in the state. The company said last month that 90,000 people had visited a website created to explain the Tucson lease program, and that it’s combing through a growing list of potential customers.

“We’re going to get early-adopters leasing these vehicles and we want to make sure their ownership experience is very positive,” said Gil Castillo, senior U.S. group manager for Hyundai’s alternative vehicle program, in an interview. “We’re going to try and vet everyone who is a hand-raiser, to know that they have reliable fueling available.”

The fuel-cell powered Tucson, made on the same assembly line in Ulsan, South Korea, that builds the gasoline version, goes about 50 miles per kilogram of hydrogen, and its two tanks hold about 5.64 kilograms (12.4 pounds). Costs of compressed gas in California range from about $5 to $10 per kilogram, depending on the facility. Fill-ups take about three minutes.

By comparison, Tesla’s top-end Model S delivers a range of more than 250 miles per charge, but repowering its depleted battery pack takes from 30 minutes, using one of Elon Musk’s “Supercharger” stations, to about eight hours at home.

Tesla’s Musk and other critics of hydrogen fuel note that producing it can be expensive and complicated. While fuel-cell vehicles themselves are pollution-free, carbon is emitted when hydrogen is made from natural gas.

Since Brouwer’s model of using natural gas from waste occurs in enclosed tanks and pipes, the carbon emissions can be more easily contained. As a result, Brouwer said, hydrogen made from this brown source meets California’s “green” fuel rules.

Brouwer said his team designed and built the Fountain Valley project with about $10 million in funding from sources including California government bodies and a U.S. Department of Energy grant. FuelCell Energy Inc. and Air Products & Chemicals Inc. provided components and worked with Brouwer to design the system.

This prototype makes enough hydrogen to supply about 200 fuel-cell vehicles. Brouwer said he has already worked out refinements that allow five times as much hydrogen production in half the space at the facility. Waste-treatment and public officials in British Columbia, Spain and the U.S. are looking into hydrogen-production based on the Fountain Valley system, he said.

There’s a limit to how much fuel waste-treatment plants can provide, he said. Installing similar hydrogen-making systems at most of California’s major waste-treatment plants would generate enough hydrogen to power about 10 percent of all the cars on the state’s roads, Brouwer said.

“We use an incredible amount of fuel for transportation, and this particular source gets you just part of the way there.”

The rest could be supplied by converting conventional natural gas, until hydrogen sources with even less carbon become available, Castillo said.

“There’s lots of natural gas, so that’s going to take care of most of the fuel,” Castillo said. “It’s also true that we can get some of the hydrogen from waste we all produce every day.” (Bloomberg)